The present invention relates to testing electronic components, and, more particularly, to a universal test fixture for electrically connecting electronic components to electronic test logic.
Integrated circuit electronic components are rapidly replacing conventional, discrete, long leaded components in electronic instruments such as communications equipments, radio and television, computers and the like. Typically, such integrated circuit components comprise a housing containing an integrated circuit chip, and having a plurality of metallic leads or pins depending downwardly from the housing. Inasmuch as high density circuit board assemblies may comprise a very large number of components, it may prove difficult and time-consuming to identify a defective component. Also, a defective component may damage other components in the assembly. Thus, it is desirable to test components prior to mounting of the components in a circuit assembly. With older components such as discrete long leaded resistors and capacitors, incoming testing generally is simple to perform since such components generally comprise only two leads. Also, once a discrete component has been tested as "good", generally nothing in the manufacturing process short of physically observable destruction, e.g. crushing, or the like, will render the component "bad", i.e. unsuitable for service at its intended operational parameters.
On the other hand, testing of integrated circuits is cumbersome, costly, and time-consuming because of the structure of the components to be tested and the numerous configurations possible. Moreover, integrated circuits can be essentially instantly destroyed by a single discharge of static electricity at any point in the manufacturing process. Thus, the later in the manufacturing process that component testing can be accomplished, the higher the probability that the components in a completed assembly all will be in proper working order. To that end, it would be desirable to test the components as part of component placement and insertion machinery after contact with human operators and their potential for transferring static charges to the components has been eliminated. The problem can be appreciated best with reference to FIGS. 1-3 taken in conjunction with FIG. 4 where FIGS. 1-3 depict the physical structure of the types of components at issue and FIG. 4 depicts the state of the prior art with respect to testing them. Typically, the components 10 comprise a housing 12 containing an integrated circuit chip (not shown) therein. The chip has its leads electrically connected to a plurality of metal leads or pins 14 extending downward from the housing 12. In use, component 10 is electrically and mechanically attached to a circuit board by soldering the leads or pins 14 directly to the circuit board lands and/or board apertures. Alternatively, leads 14 may be inserted into a socket assembly having individual pin receiving slot connectors which in turn are electrically and mechanically attached to the circuit board lands and/or apertures.
As represented by the drawing figures, the typical component 10 is either rectangular or square and has either two parallel rows of leads or pins 14 or four rows of leads or pins 14 as depicted in FIGS. 1 and 2, respectively. Leads or pins 14 depend from opposite sides of the component as shown in FIGS. 1 and 3, terminating in tips 16 lying substantially in a common plane.
In prior art test apparatus such as that generally indicated as 18 in FIG. 4, a plurality of sockets 20, 22 are provided for the varous pin configurations and pin spacings of the components to be tested. Thus, in the apparatus 18 of FIG. 4 there is a socket 20 for receiving components such as that of FIG. 1 and another socket 22 for receiving components such as that of FIG. 2. The sockets 20,22, in turn, are electrically connected to computer based test logic 24 by multi-conductor connectors 26. Respective ones of pin connectors 28 in sockets 20, 22 are connected to respective ones of the plurality of electrical conductors (not shown) within multi-conductors connectors 26 so as to be individually sensible by the test logic 24 in its testing procedure. The construction of the test logic is well known in the art. As can be appreciated, component testing with prior art test fixtures like that of FIG. 4 is inconvenient and requires a plurality of dedicated test fixtures since components with other pin spacings, widths and/or configurations could not be tested in the apparatus of FIG. 4 since they would not fit into the sockets 20, 22.
It is thus an object of the present invention to overcome the aforesaid and other disadvantages of the prior art and to provide a universal test fixture capable of testing various size and shape components having a plurality of pins.
It is another object of the present invention to provide a universal test fixture capable of testing components having pins at various spacings, and configurations.
It is yet a further object of the present invention to provide a test fixture for electronic components which is simple and easy to use, and one which is adapted for automatic in-line testing of components immediately prior to their assembly onto a printed circuit board.
Other objects and benefits of the present invention will become apparent from the detailed description contained hereinafter taken in conjunction with the drawing figures which accompany it.